The risk of Parkinson's disease with exposure to pesticides, farming, well water, and rural living

TLDR

The study evaluated whether pesticide exposure, farming, well water use, and rural living increase Parkinson’s disease risk in adults ≥ 50 in Detroit. A population‑based case‑control design enrolled 144 PD patients and 464 matched controls, frequency‑matched on age, race, and sex. After adjusting for demographics and smoking, occupational herbicide (OR 4.10) and insecticide (OR 3.55) exposure, as well as farming (OR 2.79), were significantly linked to PD, while fungicide use, rural residence, and well water use were not, and these associations persisted independently of one another, indicating that farming’s risk cannot be fully attributed to pesticide exposure.

Abstract

We assessed exposure to pesticides, farming, well water use, and rural living as risk factors for Parkinson's disease (PD) in a population-based case-control study consisting of men and women ≥50 years of age who had primary medical care at Henry Ford Health System in metropolitan Detroit. Enrolled PD patients (n = 144) and control subjects (n = 464) were frequency-matched for age, race, and sex. When adjusted for these variables and smoking status, there was a significant association of occupational exposure to herbicides (odds ratio [OR], 4.10; 95% CI, 1.37, 12.24) and insecticides (OR, 3.55; 95% CI, 1.75, 7.18) with PD, but no relation was found with fungicide exposure. Farming as an occupation was significantly associated with PD (OR, 2.79; 95% CI, 1.03, 7.55), but there was no increased risk of the disease with rural or farm residence or well water use. The association of occupational exposure to herbicides or insecticides with PD remained after adjustment for farming. The association of farming with PD was maintained after adjustment for occupational herbicide exposure and was of borderline significance after adjustment for occupational insecticide exposure. These results suggest that PD is associated with occupational exposure to herbicides and insecticides and to farming and that the risk of farming cannot be accounted for by pesticide exposure alone.